Support
Tongue Weight: Trailer Hitch
Getting a good reading
Before you start
- Level, firm pavement (not grass or gravel that can sink), engine off, in park, parking brake on.
- Weight-distribution bars unhooked; trailer on its jack beside the ball; trailer wheels chocked.
- Phone flat on the floor or console, top toward the windshield, out of direct sun, doors closed. It settles for a minute before the first reading.
- Keep your weight in Settings up to date: you are the calibration weight. A bathroom scale is fine.
"Waiting for the truck to move"
Each step waits until the truck has actually changed (you sat down, the coupler dropped) and then held still. If you're slow to get there, that's fine; it waits. If nothing should change, tap "Capture now".
"The truck never held still"
Wind, someone leaning on the truck, or a person moving inside. Wait for a calm moment and keep everyone off the truck while it reads.
"The truck didn't settle back"
Leaf springs can stick. Push down firmly on the tailgate twice after each step and let go; the spoken steps remind you. A phone warming up in the sun can do it too: move it into the shade and let it settle.
"The truck leveled itself"
Air-ride and self-levelling suspensions lift the truck back up after it's loaded, so the tilt no longer shows the load. Those vehicles can't be measured this way; use a scale.
Understanding the result
Why a range, not one number?
Springs get stiffer as they're loaded. Calibrating once, empty, would under-read; calibrating empty and loaded brackets the true value. On ordinary leaf springs the range is tight; on suspensions that stiffen a lot it's wider, and the result says so.
What do the verdicts mean?
- In range: the whole range sits inside 10–15% of your trailer's weight.
- Light: sway risk: the whole range is under 10%.
- Heavy: the whole range is over 15%.
- Verify at a scale: a 10% or 15% limit falls inside the range, so the phone can't decide. A scale can.
Where do I enter my trailer's weight?
In the rig: its loaded weight, the way you tow it. A truck-stop weigh is the best source; the trailer's sticker shows its empty and maximum weights.
Can it measure fifth-wheel pin weight?
Not yet. It measures ball-hitch trailers. Pin weight is planned.
Subscription
What's free?
One complete measurement of one rig, in full, and the demo truck, always.
What does Pro add?
Unlimited measurements, every rig, the full history and the payload check. $4.99 a month or $29.99 a year (7-day free trial on the annual plan).
How do I cancel or restore?
Cancel in iPhone Settings → your name → Subscriptions. Restore in Tongue Weight → Settings → Restore purchases.
Contact
Email support@bulpara.com. If it's about a reading, include your vehicle type, its rear suspension, your trailer's weight and a screenshot of the result.